Powered aquatic vessels are well known. Such vessels typically include at least one hull having one or more engines accommodated therein. A mechanical output of each engine is coupled to one or more propellers which are submerged in operation for providing propulsion through water. Moreover, a vessel includes a steering arrangement which involves at least one of pivoting one or more rudders or pivoting one or more propeller assemblies to control a direction of travel and, in the case of stern drive or outboard engines, pivoting the engines to control the direction of travel.
Referring to FIG. 1, there is shown a simplified plan view of a boat indicated generally by 10. The boat 10 may be, for example, a high speed pleasure boat, a high performance fishing vessel, a yacht, or similar vessel. The boat 10 includes an elongated hull 20 having a tapered front bow region at a top of FIG. 1, a truncated rear stern region at a bottom of FIG. 1, a starboard region at a right-hand side of FIG. 1, and a port region at a left-hand side of FIG. 1. Moreover, the boat 10 includes a first port-side engine and an associated drive 30 pivotable in operation by an angle α1 in respect of a longitudinal axis 40 as shown. Furthermore, the boat 10 includes a second starboard-side engine and an associated drive 50 pivotable in operation by an angle α2 in respect of a longitudinal axis 60 as shown. The longitudinal axes 40, 60 are mutually parallel and also parallel to a general longitudinal axis of the hull 20 orientated from the bow region to the stern region. The engines 30, 50 have associated therewith mutually counter-rotating duo-prop propellers, for example, as described in published International Patent Application No. WO 2004/074089 (PCT/SE2004/000206) (Volvo Penta AB). The counter-rotating propellers are either configured in pushing mode or in traction mode depending upon implementation of the boat 10.
The boat 10 further includes a control unit 70 coupled in communication with servo actuators associated with the drives 30, 50 for controlling their orientation angles α1, α2, their power output, and also a direction of rotation of their one or more propellers, namely forward or reverse. The servo actuators (not shown) are optionally implemented using hydraulic actuators or electric motors with associated angular and/or position sensors. Coupling from the control unit 70 is optionally implemented by at least one of a mechanical connection, electric connection, fiber optical connection, and/or wireless communication. The control unit 70 is also coupled for communication with a steering console 80 by which a user is able to steer and control a speed of travel of the boat 10. The steering console 80 includes a rotatable steering wheel 90. The steering console 80 also includes a lever arrangement 100 comprising one or more levers for controlling a direction of rotation of propellers associated with the first and second engines 30, 50 respectively, and also average power output delivered from the engines 30, 50 to their associated propellers. If a fishing boat, and particularly, a deep-sea fishing boat, the boat 10 conventionally has a length on the order to 12 to 15 meters, often referred to by convention as a “40 foot” boat.
Operation of the boat 10 will now be described. When traveling in a forward direction, the lever arrangement 100 is controlled by the user for specifying whether the engines are coupled via the transmission or drive 30, 50 to their associated propellers in a forward gear or a reverse gear. For propelling the boat 10 in a forward direction, the drives 30, 50 associated with the engines are both set in forward gear. Moreover, for propelling the boat 10 in a reverse direction, the drives 30, 50 associated with the engines are both set in reverse gear. The lever arrangement 100 also enables the user to specify a general combined output power of the two engines to their associated propellers. Rotation of the steering wheel 90 correspondingly controls the angles α1, α2 which are substantially mutually similar in operation; in other words, the drives 30, 50 are operable to angularly pivot in synchronism so that substantially α1=α2 as illustrated in FIG. 1. Moreover, control of direction of travel of the boat 10 in forward and reverse directions is arranged to be akin to selecting forward and reverse gears in a road vehicle. Such disposition of the steering console 80 renders the boat 10 as similar as possible for steering purposes to the user as driving a road vehicle, albeit with effectively back-wheel steering.
The inventors have appreciated that the boat 10 illustrated schematically in plan view in FIG. 1 is not capable of providing a degree of maneuverability that is desirable for certain aquatic operations, for example chasing after large fish, for example, marlin, sailfish, and the like.
Performance of the boat 10 is can be improved by increasing power output of the engines, by increasing responsiveness of the aforementioned servo actuators, and by increasing a maximum range for the steering angles α1, α2. However, such modifications potentially compromise a design of the hull 20, add additional weight to the boat 10, and potentially increase the cost of manufacturing the boat 10.
Thus, the present invention is concerned with addressing a problem that contemporary aquatic vessels are not as maneuverable as desired, especially for specialized operations such a hunting big fish.